Water-flow silencer



April 1944- w. F. PETERSON ET AL 2,346,542

WATER-FLOW .SILENGER Original Filed Aug. 11, 1937 Patented Apr. 11, 1944WATEE-FLOW SILENCER Walker F. Peterson and Albert U. Walter, Baltimore,Md., assignors to Quiet Flow Devices, Inc., Baltimore, Md, a corporationof Maryland Original application August 11, 1937, Serial No. 158,622,now Patent No. 2,288,945, dated May Divided and this application April24, 1939, Serial No. 269,764

9 Claims.

This invention relates to means for preventing noise incident to theflow of water at high velocities and is particularly desirable in flowcontrol devices. This application is a division of our applicationNumber 158,622, filed August 11, 1937, which has matured into Patent N0. 2,283,945 granted May 26, 1942.

One of the objects of the invention is the provision of means foravoiding the noise which occurs when a jet or stream of water at highvelocity is deflected.

In our prior patents, 2,037,737; 2,089,223 and 2,089,224, we havedescribed devices for controlling the flow of liquids with substantialquietness. We have found, however, that noises may arise at other pointsof the system although these noises are to be distinguished from thoseproduced in retarding or throttling liquids under the conditions statedin said patents. For example, when a jet of water at high velocityencounters a surface, noise is produced. The velocity referred to is notthat at the point of discharge from the nozzle, but at the point ofimpact with the surface. Although th velocity of the discharged streamdecreases rapidly, as the jet mixes with water already present in thechamber, yet space and constructional considerations often require thatthe jet be deflected at a relatively short distance from the nozzle ororifice from which it is discharged and before it velocity issufficiently reduced so that it does not make noise when it encounters asurface and is deflected.

Accordingto the present invention, noise at this point is substantiallyprevented by providing an impact surface of a definite character forreceiving the jet. The character of this surface is of primaryimportance in determining the critical velocity of the jet at which thenoise occurs.

An illustrative form of practicing the present invention is shown in theaccompanying drawing, in which:

Figure 1 is a fragmentary sectional View of a conventional flush tankfor a toilet, with a device of the present nature employed therein.

Figure 2 is a perspective view of the lower end of the supply pipe,showing a silencing device thereon.

In this drawing, a conventional flush tank I of the type used fortoilets i illustrated as having a flushing pipe connection 2, commonlycalled a tail piece, by which it is connected to the closet bowl. Theupper end of this flushing pipe is normally closed by the flush valve 3which may be operated for flushing by the usual trip lever (not shown).The flush tank is to be filled with water to a predetermined level, thiswater being introduced from a water supply connection 4 through theso-called supply pipe 5 which has an enlarged flange 38 at the floor ofthe tank and extends upwardly in the flush tank and has, at its upperend, a ballcock body 6 rigidly secured thereto. In the body 6 is avertically movable, valve-closure member I for engaging a valve seat.

Th valve closure member I is actuated by the float l l, which isconnected by a float stem Ho and a linkage 39 for forcing the valveclosure member I downwardly and into closed position when the waterlevel in the tank has risen to the predetermined level. Such a linkageis set out and claimed in our copending application Ser. No. 269,765,filed Apr. 24, 1939.

The water which passes the valve closure member l in an open position ofthe latter, moves partly through the refill tube 8 while the bulkthereof is discharged through the so-called drop tube or discharge tubeI 2 into the tank. The discharge tube |2 is illustrated as being aflattened tube of the type described and claimed in either our Patent2,037,737, granted April 21, 1936, or our Patent 2,089,224, grantedAugust 10, 1937, and delivers a'thin sheet of water in a downwarddirection. In either case, the discharge tube l2 functions as a flowretarding device and the discharge or jet issuing therefrom is of highvelocity.

In order to avoid noise of splashing, the lower or discharge end of thetube I 2 must be below the minimum level of the water in the tank, whichmeans that it must be within 1 inch or less of the bottom of the tank inpresently standard structures. It has been found that under therelatively high pressures of water supply systems of various cities,this high velocity jet would cause a noise upon striking the bottom ofthe tank I or the flange 38 of the supply pipe 5.

In the illustrated form, an impact member 48 is formed integrally withthe casting which provides the flange 38 and supply pipe 5 and is solocated as to receive the jet from the discharge tube l2. The upper orimpact surface of the member 40 may be at any angle to the direction ofthe jet issuing from the discharge tube. In order to secure th desireddispersion of the water in the illustrated case and to facilitatecasting, this surface is shown as sloping away from the axis of thedischarge tube I2 and inclining at a slight angle in each direction fromthe center of its length. The angle of impact to be employed dependsupon the deflection to be accomplished.

It has been found that when the upper or impact surface of the member isprovided with roughening, the roughening causes an action in the natureof diffusion, so that the jet is broken up into innumerable fine streamswhich dissipate into the main body of water without noise. The surfaceof castings as ordinarily produced is not sufiiciently rough or sharp intexture for the elimination of noise thereby: and this is particularlytrue after the casting has been rumbled or sand blasted in the usualway. As pointed out in our aforesaid prior patents, various factorsinfluence the critical velocity, above which noise occurs: and referenceis made theretofor a discussion of these factors.

By roughening or roughened surface throughout this specification andclaims is meant a surface having elevations and depressions throughoutits efiective area of the nature of the surface of ordinary sand paperof the types known commercially as #3/0 to #3, or similar to thoseresulting from cutting full or partial depth grooves with the adjacentgrooves spaced 16 to 80 to the inch, orsimilar to the surface of asingle or double cut file with a coarseness from bastard to dead smooth,or a knurled surface of like spacing. With such surfaces the successiveelevations and depressions are spaced from one another by distances ofthe order of one-sixteenth to oneeightieth of an inch, and quietness isattained with all normal supply pressures of water while employing thestructure illustrated in the drawme.

It has been found that the minimum depth of the depressions between theelevations should not be less than 0.005 inch.

In Figure 2, the impact surface of the illustrated member 40 is shown ashaving a plurality of grooves of the aforesaid character formed thereon.Specifically, the oughening is shown as a series of ribs and groovesspaced twenty to an inch with the grooves having a depth of about .020inch, and directed parallel to the thin sheet of water discharged fromthe flattened drop tube l2.

It is obvious that the invention is not limited only to the illustratedforms shown, but it may be employed in many ways within the scope of theappended claims. t

We claimf 1. An assembly for the discharge of a liquid comprising asupply pipe, a passageway communicating with the supply pipe andincluding means for restricting the flow of liquid through thepassageway, said passageway having an orifice for directing a liquid jetsubstantially parallel to the supply pipe and a member psitioned on thesupply pipe at an angle to the liquid jet discharged from saidpassageway for receiving the impact thereof, said member having jet forreceiving the impact thereof, said member having an imperforate impactreceiving surface whichis characterized by successive elevations anddepressions, the elevations being spaced apart distances of the order ofone-sixteenth to one-eightieth of an inch, and means for maintaining asupply of liquid about said roughened surface substantially throughoutthe duration of flow of said jet.

3. A quiet discharge structure for liquids, comprising a chamber forreceiving discharged liquid and for retaining a supply of liquid thereinsubstantially throughout the course of the discharge, a discharge nozzleand means for delivering liquid therethrough into the chamber, saidnozzle ,being located beneath the liquid level in the chambersubstantially throughout the period of delivery of liquid through thenozzle, and means presenting a roughened surface opposite to and in thepath of the jet of liquid from said nozzle, said roughened surfacehaving successive elevations and depressions spaced apart betweenonesixteenth and one-eightieth of an inch.

4. A quiet discharge structure for liquids, comprising a conduit havinga discharge opening, and a chamber for receiving liquid dischargedthrough said opening, said chamber including means for maintainingliquid above the level of said discharge opening'and means presenting animperforate roughened surface opposite said opening and in the path ofthe jet of liquid therefrom, said roughened surface having successiveelevations and depressions spaced apart between one-sixteenth andone-eightieth of an inch.

5. A quiet discharge device for liquids, comprising a conduit having adischarge opening through which the liquid may flow in the form of athin sheet, a chamber for receiving liquid discharged through saidopening and for retaining liquid above a predetermined minimum liquidlevel during such discharge, said chamber including means located belowsaid minimum liquid level presenting a roughened surface opposite and inthe path of the sheet of water, said roughened surface having successiveele- -vations and depressions in the form of ribs spaced apart betweenone-sixteenth and oneeightieth of an inch and disposed substantiallyparallel to the said sheet.

6. A quiet discharge device for liquids, comprising a conduit having adischarge opening through which the liquid may flow in the form of athin sheet, a chamber for receiving liquid discharged through saidopening and for retaining liquid above a predetermined minimum liquidlevel during such discharge, said conduit opening being located belowsaid minimum liquid level, said chamber including means located belowsaid minimum liquid level presenting a roughened surface opposite and inthe path of the sheet of water, said roughened surface having successiveelevations and depressions in the form of ribs spaced apart betweenone-sixteenth and one-eightieth of an inch and disposed substantiallyparallel to the said sheet.

'7. A device for quietly receiving the impact of a liquid jet moving athigh velocity, comprising means having successive elevations anddepressions spaced apart between one-sixteenth and one-eightieth of aninch for providing a roughened surface disposed across the path of thejet for deflecting and breaking up the same into innumerable finestreams, and means for maintaining a supply of liquid about saidroughened surface substantially throughout the duration of flow of saidjet.

8. A device for quietly receiving the impact of a liquid jet moving athigh velocity, comprising means having successive elevations anddepressions spaced apart between one-sixteenth and one-eightieth of aninch for providing a roughened surface disposed in the path of and at anangle to the jet for deflecting and breaking up the same intoinnumerable fine streams, and means for maintaining a supply of liquidabout said roughened surface substantially throughout the duration offlow of said jet.

9. A quiet flow device for a liquid jet having the form of a thin sheet.comprising a member extending across the liquid jet for receiving theimpact thereof, said member including an impact receiving portion havingtwo surfaces at an angle to each other, the edge formed at the junctureof the surfaces being in the path of the jet and substantially at aright angle to the plane of the thin sheet, said surfaces havingsuccessive elevations and depressions, the elevations being spaced apartdistances of the order of onesixteenth to one-eightieth of an inch.

WALKER F. PETERSON. ALBERT U. WALTER.

